000
FXUS63 KMKX 141110
AFDMKX
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
610 AM CDT Wed Mar 14 2018
.UPDATE...
No changes at this hour.
&&
.AVIATION(12Z TAFS)...
VFR conditions are expected over the next 24 hours, with just
passing high clouds.
The main concern for aviation will be surface winds. Southwest
winds will increase later this morning, peaking early to mid
afternoon with gusts between 25 and 30 kt. Winds will become more
westerly with time, and eventually northwesterly later this
evening. Gusts will settle down after sunset, but a steady
northwest to north breeze is expected for most of tonight.
&&
.PREV DISCUSSION... (Issued 240 AM CDT Wed Mar 14 2018)
SHORT TERM...
Today and Tonight...Forecast Confidence is High...
After a cool start in the upper teens to low 20s, temperatures
will warm nicely today, with afternoon highs in the mid 40s, along
with plenty of sunshine. Temperatures will be helped along by
gusty southwest winds, with gusts exceeding 30 MPH from late
morning through the afternoon hours.
A passing front will turn winds to the west late this afternoon
and then eventually from the north tonight, with gusts falling
off with sunset. Expect temperatures to fall into the low to mid
20s by daybreak Thursday.
LONG TERM...
Thursday and Friday...Forecast confidence is high.
Mid-level heights begin rising locally on Thursday as upper ridging
becomes established over the area by Friday. This will promote quiet
weather for southern Wisconsin as surface high pressure builds
equatorward from south central Canada into the western Great Lakes.
An upstream shortwave will dig into the Desert Southwest early in
the period before carving out a closed low over the central Great
Plains. This low will escort a Rockies lee cyclone, as it travels
from the Colorado Front Range into Kansas or Nebraska by Friday.
Cool, yet seasonal, temperatures are anticipated on Thursday into
Friday with highs in the upper 30s to lower 40s. Eastern areas
closer to Lake Michigan will be cooler on Friday due to onshore flow
from the east.
Friday Night through Sunday...Forecast confidence is medium.
The upper low devolves to an open-wave trough as it travels through
the Missouri and Ohio Valleys. This keeps the slowly filling surface
low to our south, with the associated moisture potentially reaching
far southern Wisconsin. While the 13.12z and 14.00z GFS
deterministic solutions brush us with some light QPF on Friday
night into Saturday morning, there is disagreement among ensemble
members regarding the surface low track, with several of them
taking it well south of the operational run (thus keeping the
precipitation to our south as well). The 13.12z ECMWF solution
came in dry, but the 14.00z run clips our southwest with some
light QPF. Given this wetter trend, will introduce slight chance
PoPs in our south for late Friday night into Saturday morning per
collaboration with neighboring offices. Precipitation type would
be snow possibly transitioning to a mix then rain late Saturday
morning as temperatures warm. We`ll need to keep an eye on thermal
profiles, with some models suggesting a period of freezing rain
is possible to our south over northern Illinois. Again, this all
hinges on how much moisture we`ll have to work with, and this is
still in question. We`ll keep fine tuning this forecast going
forward. Southeast winds and warm advection ahead of the low
should allow high temperatures to climb into the 40s, with some
areas perhaps eclipsing 50. Once again easterly locations should
be cooler with the onshore wind component.
Monday through Wednesday...Forecast confidence is medium.
Yet another shortwave passes to our south on Monday into Tuesday
with model differences in the strength and placement of the
associated surface low. The most recent GFS, Canadian, and ECMWF
solutions are farther north with the low and precipitation, so
will defer to model blended PoPs for this period. Given thermal
profiles we could see rain on Monday changing to snow Monday
night. Still plenty of time for things to change this far out in
the extended however. Near normal temperatures are likely.
AVIATION(09Z TAF Update)...
Gusty southwest winds are expected today, with gusts between 25
and 30 knots at times early this afternoon. Winds will become
westerly by late afternoon, and then northerly late tonight.
Expect VFR conditions to prevail.
MARINE...
A period of gusty southwest winds are expected today across the
nearshore waters, with peak gusts occurring this afternoon. Winds
will then become westerly late this afternoon into the evening
hours, and then northerly overnight. A Small Craft Advisory will
be in effect from early afternoon through late evening.
Winds will remain northerly through Thursday, before they become
easterly Friday ahead of a storm system that is currently expected
to pass south of the area.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory from 1 PM this afternoon to 1 AM CDT
Thursday for LMZ643>646.
&&
$$
Update...Boxell
Today/Tonight and Aviation/Marine...Boxell
Thursday THROUGH Tuesday...99